A Colorimetric Membrane-Based Sensor with Improved Selectivity towards Amphetamine

Due to their simplicity, speed and low cost, chemical spot tests are increasingly demanded for the presumptive identification of illicit drugs in a variety of contexts such as point-of-care assistance or prosecution of drug trafficking. However, most of the colorimetric reactions used in these tests are, at best, drug class selective. Therefore, the development of tests based on chemical reactions with improved discrimination power is of great interest. In this work, we propose a new colorimetric assay for amphetamine (AMP) based on its reaction with solutions of alkaline gold bromide to form an insoluble yellow–orange derivative. The resulting suspensions are then filtered onto nylon membranes and the precipitate collected is used for the visual identification of AMP. The measurement of the absorbance of the membranes by diffuse reflectance spectroscopy also allows the quantification of AMP in a simple and rapid way, as demonstrated for different synthetic and drug street samples. On the basis of the results obtained, it was concluded that the proposed procedure is highly selective towards AMP, as this compound could be easily differentiated from other common drugs such as methamphetamine (MET), ephedrine (EPH), scopolamine (SCP) and cocaine (COC).

Refining the picture: new records to the lichen biota of Italy

Based on the analysis of both historical and recent collections, this paper reports an annotated list of taxa which are new to the lichen biota of Italy or of its administrative regions. Specimens were identified using a dissecting and a compound microscope; routine chemical spot tests and standardized thin-layer chromatography (TLC or HPTLC). The list includes 225 records of 153 taxa. Twenty taxa are new to Italy, the others are new to one or more administrative regions, with 15 second records and 5 third records for Italy. Some of the species belong to recently-described taxa, others are poorly known, sterile or ephemeral lichens which were largely overlooked in Italy. Several species are actually rare, either because of the rarity of their habitats (e.g. old-growth forests), or because in Italy they are at the margins of their bioclimatic distribution. The picture of the lichen biota of Italy has now new pixels, but its grain is still coarse. Further analysis of historical collections, increased efforts in the exploration of some areas, and the taxonomic revision of critical groups are still necessary to provide more complete distributional data for new biogeographic hypotheses, taxonomic and ecological research, and biodiversity conservation.

Efficacy of commercial bacteriophage products against ESKAPE pathogens

The ever-rising prevalence of multidrug-resistant bacteria necessitates the search for a therapeutic alternative to antibiotics. Using therapeutic products based on virulent bacteriophages might provide such an alternative. The aim of our study was to evaluate the efficacy of commercial phage products and natural bacteriophage monoisolates recovered from environmental sources against clinical strains of Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa. We compiled a collection of 147 strains that were subsequently genotypes using the MLST method. The efficacy of bacteriophages was evaluated in spot tests. The highest efficacy was demonstrated by "Staphylococcal bacteriophage" (86%, effective against S. aureus), "Purified polyvalent pyobacteriophage" (87.8%, effective against K. pneumoniae), and a group of phage products against P. aeruginosa, including "Pseudomonas aeruginosa bacteriophage" (87.5%), "Complex pyobacteriophage" (79.5–90%) and "Purified polyvalent pyobacteriophage" (90–92.5%). The efficacy of "Intesti bacteriophage", which targets E. faecium, was 4.2%. The efficacy of commercial phage products against S. aureus and K. pneumoniae was higher than the efficacy of individual phage monoisolates (60% for the S. aureus phage vB_SauP-436-3w and 5.9% for the K. pneumoniae phage vB_Kp_M_ Seu621). Thus, all tested commercial phage products were highly effective against P. aeruginosa, K. pneumoniae and S. aureus. There are no commercial phage products on the market against other ESKAPE pathogens, including Acinetobacter baumannii and Enterobacter cloacae. Besides, there are no effective phage products against E. faecium. This dictates the need for new effective bacteriophages against these species.